S.H. collected and analyzed the data and wrote the paper. C.L. provided idea and suggestions for the study direction. L.M. helped solve SEM imaging issue and provided comments on SEM image analyses. P.P. gave suggestions of the usage of Mano's phylogeny.
References
Borgardt, S.J. and Pigg, K.B., 1999. Anatomical and developmental study
of petrified Quercus (Fagaceae) fruits from the Middle Miocene, Yakima
Canyon, Washington, USA. American Journal of Botany, 86(3), pp.307-325.
Corden, J. and Millington, W., 1999. A study of Quercus pollen in the
Derby area, UK. Aerobiologia, 15(1), pp.29-37.
Daghlian, C.P. and Crepet, W.L., 1983. Oak catkins, leaves and fruits
from the Oligocene Catahoula Formation and their evolutionary
significance. American Journal of Botany, pp.639-649.
Denk, T. and Grimm, G.W., 2009. Significance of pollen characteristics
for infrageneric classification and phylogeny in Quercus(Fagaceae). International Journal of Plant Sciences, 170(7), pp.926-940.
Dodd, R.S. and Kashani, N., 2003. Molecular differentiation and
diversity among the California red oaks (Fagaceae; Quercus section
Lobatae). Theoretical and Applied Genetics, 107(5), pp.884-892.
Erdtman G. 1952. Pollen Morphology and Plant Taxonomy. Angiosperms.
Almqvist and Wiksell, Stockholm. 539 pp.
Faegri, K. and Iversen, J., 1964. Textbook of pollen analysis (No. QK658
F24 1964).
Hesse, M., Halbritter, H., Weber, M., Buchner, R., Frosch-Radivo, A.,
Ulrich, S. and Zetter, R., 2009. Pollen terminology: an illustrated
handbook. Springer Science & Business Media.
Heusser, L.E., 2000. Rapid oscillations in western North America
vegetation and climate during oxygen isotope stage 5 inferred from
pollen data from Santa Barbara Basin (Hole 893A). Palaeogeography,
Palaeoclimatology, Palaeoecology, 161(3), pp.407-421.
Heusser, L., Lyle, M. and Mix, A.C., 2000. Vegetation and climate of the
northwest coast of North America during the last 500 KY:
high–resolution pollen evidence from the northern California margin.
Hipp A.L., Eaton DAR, Cavender-Bares J., Fitzek E., Nipper R., et al.
2014. A Framework Phylogeny of the American Oak Clade Based on Sequenced
RAD Data. PLoS ONE 9(4): e93975. doi:10.1371/journal.pone.0093975
Hubert, F., Grimm, G. W., Jousselin, E., Berry, V., Franc, A., and
Kremer, A., 2014. Multiple nuclear genes stabilize the phylogenetic
backbone of the genus Quercus , Systematics and Biodiversity,
12(4), pp.405-423.
Jarvis, D.I., Leopold, E.B. and Liu, Y., 1992. Distinguishing the pollen
of deciduous oaks, evergreen oaks, and certain rosaceous species of
southwestern Sichuan Province, China. Review of palaeobotany and
palynology, 75(3), pp.259-271.
Manos, P.S. and Stanford, A., 2001. The historical biogeography of
Fagaceae: tracking the Tertiary history of temperate and subtropical
forests of the Northern Hemisphere. Int J Plant Sci 162(suppl):S77–S93.
Medus, J. and Flores, G.G., 1984. Pollen morphology of some Mexican
oaks. Grana, 23(2), pp.77-84.
Mensing, S. A. (2001). Late-glacial and early Holocene vegetation and
climate change near Owens Lake, eastern California. Quaternary Research,
55(1), 57-65.
Nixon, K.C., 2002. The oak (Quercus) biodiversity of California and
adjacent regions.
Paradis E. & Schliep K. 2018. ape 5.0: an environment for modern
phylogenetics and evolutionary analyses in R. Bioinformatics 35:
526-528.
Revell LJ (2012). “phytools: An R package for phylogenetic comparative
biology (and other things).” Methods in Ecology and
Evolution , 3, 217-223.
Punt, W., Hoen, P.P., Blackmore, S., Nilsson, S. and Le Thomas, A.,
2007. Glossary of pollen and spore terminology. Review of Palaeobotany
and Palynology, 143(1), pp.1-81.
Rowley, J.R. and Gabarayeva, N.I., 2004. Microspore development in
Quercus robur (Fagaceae). Review of Palaeobotany and Palynology, 132(1),
pp.115-132.
Solomon, A.M., 1983. Pollen morphology and plant taxonomy of red oaks in
eastern North America. American Journal of Botany, pp.495-507.
Solomon, A.M., 1983. Pollen morphology and plant taxonomy of white oaks
in eastern North America. American journal of botany, pp.481-494.
Williams GJ (2011). Data Mining with Rattle and R: The art of
excavating data for knowledge discovery , series Use R!
Springer. http://www.amazon.com/gp/product/1441998896/ref=as_li_qf_sp_asin_tl?ie=UTF8&tag=togaware-20&linkCode=as2&camp=217145&creative=399373&creativeASIN=1441998896.
Zetter, R., Ferguson, D.K. and Mohr, B.A., 2007. Discriminating fossil
evergreen and deciduous Quercus pollen: a case study from the Miocene of
eastern China. Review of Palaeobotany and Palynology, 145(3),
pp.289-303.